cargo component serve does not show in cargo component --help

[danbugs]

cargo component serve does not show in cargo component --help and this is because serve isn't a directly supported cargo-component command, like:

cargo-component/src/bin/cargo-component.rs

Lines 67 to 76 in 5063442

	enum Command {
	Add(AddCommand),
	// TODO: Init(InitCommand),
	New(NewCommand),
	// TODO: Remove(RemoveCommand),
	Update(UpdateCommand),
	Publish(PublishCommand),
	// TODO: Yank(YankCommand),
	// TODO: Vendor(VendorCommand),
	}

And, instead, it is a cargo command (not really, but, as per the code's nomenclature, yes):

cargo-component/src/lib.rs

Lines 74 to 83 in 5063442

	enum CargoCommand {
	#[default]
	Other,
	Help,
	Build,
	Run,
	Test,
	Bench,
	Serve,
	}

I think it would be helpful to add serve as a proper cargo-component command for discoverability of the feature*.

[primoly]

When I added serve I just treated it as a special case of run. That’s why it’s in CargoCommand instead of Command.

I didn’t know that CargoCommands don’t get help support. Maybe this should be added for all of them, not just serve. It seems a bit strange that --help doesn’t list all commands available. A user has to guess that cargo component has for example its own run command, but fmt is just propagated. The current --help makes it seem like all subcommands except for the ones in the Command enum are propagated.